coincidental

adjective

co·​in·​ci·​den·​tal (ˌ)kō-ˌin(t)-sə-ˈden-tᵊl 

1

: resulting from a coincidence

a coincidental resemblance

2

: occurring or existing at the same time

coincidental deaths

Synonyms

• coincident
• concurrent
• synchronous
• synchronic

Examples of coincidental in a Sentence

The fact that he and his boss went to the same college was purely coincidental.

the nearly coincidental deaths of Princess Diana and Mother Teresa

Recent Examples on the Web

Those distinctions are not coincidental. —Graeme Wood, The Atlantic, 2 Sep. 2025

The two targets were fighting over how to go about developing the land, which lent some tips to the investigation of their deaths, but there are also a few red herrings and coincidental events that complicate the case. —Dessi Gomez, Deadline, 28 Aug. 2025

These placements aren’t coincidental but tactical. —Connie Etemadi, USA Today, 28 Aug. 2025

In the case of Anthony, his promotion is no worse than coincidental to Boston's turnaround. —Jon Paul Hoornstra, MSNBC Newsweek, 25 Aug. 2025

Word History

Etymology

coincident + -al entry 1

First Known Use

circa 1800, in the meaning defined at sense 1

Rhymes for coincidental

• developmental
• environmental
• experimental
• intersegmental
• nongovernmental
• transcontinental
• unsentimental
• accidental
• compartmental
• continental
• detrimental
• elemental

Kids Definition

coincidental

adjective

co·​in·​ci·​den·​tal (ˌ)kō-ˌin(t)-sə-ˈdent-ᵊl 

1

: resulting from a coincidence

a coincidental resemblance

2

: occurring or existing at the same time

coincidentally

-ˈdent-lē

-ᵊl-ē

adverb